1. Field of the Invention
The present invention relates to a method which, in a process of manufacturing where high cleanliness is required to a ball/roller bearing, cleans an assembled ball/roller bearing before supplying oil or grease.
2. Description of the Related Art
Conventionally, as a method for cleaning a mechanical part, an ultrasonic cleaning method has been mainly used. In this ultrasonic cleaning method, for example, as shown in FIG. 14, a bearing 1 to be cleaned stored in a washing basket 50 is cleaned within a cleaning vessel 22 which includes an ultrasonic vibration plate 20 mounted on the bottom portion thereof and is filled with cleaning liquid 24.
Also, as a method for cleaning a ball/roller bearing, a patent is disclosed, for example, in Japanese Patent Unexamined Publication No. Hei.11-138111 (JP-A-11-138111). In this cleaning method, a bearing to be cleaned is disposed on a rotary table where cleaning liquid is jetted onto the bearing from inside and outside as well as from above and below, thereby cleaning the bearing.
However, in the above-mentioned conventional ultrasonic cleaning method, due to the characteristics of ultrasonic waves, the ultrasonic waves are not able to effect the interior parts of the bearing to be cleaned, which results in insufficient cleaning. Especially, since the bearing to be cleaned is simply immersed in the cleaning liquid, it is difficult to completely remove dirt particles existing between the rolling bodies and retainer of the bearing to be cleaned.
Also, in the latter ultrasonic cleaning method, although the area of the bearing where the jetted cleaning liquid is applied can be cleaned, the cleaning liquid is splashed back from the portions of the bearing where it is applied, so that the portions of the bearing, where the jetted cleaning liquid cannot be applied directly, cannot be cleaned to a satisfactory degree. Therefore, it is difficult to completely remove dirt particles between the parts of the bearing to be cleaned, for example, between the rolling bodies and retainer of the bearing to be cleaned. Also, referring to an ultrasonic cleaning apparatus employed in enforcing the ultrasonic cleaning method, the structure thereof is complicated: that is, the ultrasonic cleaning apparatus is capable of cleaning a ball/roller bearing of a relatively large size but is not suitable to clean a ball/roller bearing of a small size.